what is lm358

[Davaliao]

LM358——Dual Low Power Operational Amplifier

Utilizing the circuit designs perfected for recently introduced Quad
Operational Amplifiers, these dual operational amplifiers feature 1) low
power drain, 2) a common mode input voltage range extending to
ground/VEE, 3) single supply or split supply operation and 4) pinouts
compatible with the popular MC1558 dual operational amplifier. The LM158
series is equivalent to one–half of an LM124.
These amplifiers have several distinct advantages over standard
operational amplifier types in single supply applications. They can operate at
supply voltages as low as 3.0 V or as high as 32 V, with quiescent currents
about one–fifth of those associated with the MC1741 (on a per amplifier
basis). The common mode input range includes the negative supply, thereby
eliminating the necessity for external biasing components in many
applications. The output voltage range also includes the negative power
supply voltage.
• Short Circuit Protected Outputs
• True Differential Input Stage
• Single Supply Operation: 3.0 V to 32 V
• Low Input Bias Currents
• Internally Compensated
• Common Mode Range Extends to Negative Supply
• Single and Split Supply Operation
• Similar Performance to the Popular MC1558
• ESD Clamps on the Inputs Increase Ruggedness of the Device without

[clark]

I Know Without adding another supply, an LM358 could be used if the REF(+) input is not to be set above 3.5V.

[rajni]

The LM158 series consists of two independent, high gain, internally frequency compensated operational amplifiers which were designed specifically to operate from a single power supply over a wide range of voltages. Operation from split power supplies is also possible and the low power supply current drain is independent of the magnitude of the power supply voltage.

[bcct]

The LM358 is old, inexpensive and has poor specs today. Its maximum input offset voltage is shown on its datasheet as 7mV at room temperature so the error on the first opamp could be as high as 70mV and the error on the second opamp could be as high as 3.8V.
It is probably too noisy to amplify your very low levels.

[aggarwalyogesh786]

Basically its a low power dual operational amplifier....
it has certain features...
Large DC voltage gain: approx 100dB
it can work on single as well as dual supply
large output voltage swing
low input offset voltage
[http://www.national.com/mpf/LM/LM358.html#Overview] check this for more information[/url]